1. Field of the Invention
The present invention relates to a door locking system for a motor vehicle which locks and unlocks a door lock such as a trunk lid lock or a tailgate lock by motor power or manual power.
2. Description of the Prior Art
In a typical door locking system for car doors including a trunk lid and a tailgate, a striker is fixed to one of a car body and a car door, a base plate having a striker leading slot is fixed to the other of the car body and the car door, and a latch and a pawl for locking and unlocking the striker are pivoted on the base plate on opposite sides of the striker leading slot, respectively.
A typical door locking system is conventionally provided with a powered operation device and a manual operation device. The powered operation device is provided with a rotary pressing member which is driven by a motor to press the pawl so that it rotates in a lock releasing direction to disengage the latch so that the latch releases from the striker. The manual operation device is provided with an opening lever which is engaged with the pawl to rotate the pawl in the lock releasing direction by a manual operation. The opening lever is conventionally provided as a member independent of the rotary pressing member. This means that the rotary pressing member and the opening lever are respectively pivoted about different rotational shafts. This structure increases the number of elements and the size of the door locking system. Moreover, due to this structure, the direction in which load is applied to the rotational shaft of the pawl when the pawl is rotated by the rotary pressing member is different from the direction in which load is applied to the rotational shaft of the pawl when the pawl is rotated by the opening lever. This cannot ensure a smooth movement of the pawl because the pawl is pressed by the rotary pressing member and the opening lever from different directions.
In addition, in the conventional door locking system, since the rotary pressing member is supported by the base plate to be freely rotatable, it is necessary to provide the door locking system with an independent rotational shaft about which the rotary pressing member is freely rotatable. Providing such an independent rotational shaft causes a problem in the positioning accuracy between the independent rotational shaft and associated elements, an increase in the number of elements of the door locking system, and an increase in the number of man-hours for assembly.
Moreover, in typical power door locking systems, the rotary pressing member applies pressure to the pawl via a roller which is rotatably fixed to the pawl at a point thereon which comes into contact with the rotary pressing member when the rotary pressing member applies pressure to the pawl. Providing the pawl with such a roller that is provided as an element independent of the pawl causes a problem in the positioning accuracy between the pawl and the roller, increases the number of elements of the power door locking system, and increases the number of man-hours for assembly.
On the other hand, typical door locking systems are generally provided with a luggage compartment lamp switch which turns ON and OFF a luggage compartment lamp when a trunk lid lock or a tailgate lock is unlocked and locked, respectively. The luggage compartment lamp switch includes a stationary terminal strip serving as one of positive and negative electrodes of the luggage compartment lamp switch, and a movable terminal strip serving as the other of positive and negative electrodes of the luggage compartment lamp switch. The movable terminal strip is in contact with the stationary terminal strip when the locking system is in the lock release position in which the striker is disengaged from the latch, and the movable terminal strip is disengaged from the stationary terminal strip when the locking system is in the lock position in which the striker is engaged with the latch.
Conventionally, the structure providing electrical isolation between the stationary terminal strip and the movable terminal strip is complicated to prevent a malfunction from occurring, thus increasing the cost of production.